regular language

Question

Stare true and false

Is this  regular ? 

now if it is not regular then i want to change in the question in place of (a+b)+ if it is (a+b)* then ??

Comments

i am thinking that the language is not regular but after the change which i done the language become regular

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not regular,

if it is (a+b)*  regular

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after change the language is $(a+b)^*$

so, regular

Answer 1

answer of your first question why not regular-It is not regular since you will have to first accept wwr which is a CFL , and then you can have any no of a's and b's ,So you can construct a NPDA for this by accepting wwr by final state and then whenever u see either a or b ,and top of stack is Z0 which is the stack symbol then don't make any transitions to any other state , remain in the same final state and let the stack symbol remain same as Z0 only .

Comments

What about the case (a+b)*

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it will become regular ....no string matching